The present invention relates generally to data and voice communications, and more particularly, to a system and method for implementing V.90 central site mode functionality at a customer premises.
Modern data and voice communications have progressed to a point at which it is now possible to implement communication systems that are capable of delivering very large amounts of information to individual customer premises locations. For example, it is possible to implement digital subscriber line (DSL) technology at a residential location over the existing copper wire pair that has served in the past to support only a plain old telephone service (POTS) communication system. Other digital technology, similar in the service provided but differing in the approach in which implemented, is also available in addition to the above mentioned DSL technology. Examples of this technology include multiple virtual lines (MVL), asymmetric digital subscriber lines (ADSL), etc., whereby the result is the establishment of a digital communication interface at a customer premises, the digital connection provided over a single copper wire pair.
One of the benefits of this digital technology is the ability to provide a high speed data connection (on the order of 128 kilobits per second (Kb/s) and higher), while simultaneously providing an embedded channel over which conventional voice traffic may be communicated.
Unfortunately, there remain many customer premises locations to which the latest digital technology is unavailable, or at which the customer has chosen an existing analog communications technology, such as an analog modem, with which to send and receive information. The latest and fastest analog modems are ones that comply with the V.90 communication standard and connect a customer premises, also referred to as an xe2x80x9cend-pointxe2x80x9d to a telephone company central office via a conventional copper wire pair. Typically, the central office to which the end-point V.90 modem is connected is connected to another central office via a four wire digital connection, such as a T1/E1, synchronous optical fiber network (SONET) or some other high speed, high capacity digital connection. This network can be a public switched telephone network (PSTN), a public data network (PDN), or the like.
The above-mentioned two wire connection is one in which signals traveling in both directions are combined over the single wire pair, while the four wire connection maintains the signals traveling in each direction on a separate wire pair.
This central office typically connects via a four wire digital connection to another modem compatible with the V.90 specification. This modem is typically referred to as a xe2x80x9ccentral sitexe2x80x9d modem, and typically resides at a service provider location, such as an Internet service provider (ISP). So, in this communication scheme, one of the V.90 modems must connect to a central office via a digital four wire interface in order to provide communication services to a customer premises, or end-point. In the above-described V.90 communication environment, the data transfer rate between the end-point and the central site is asymmetrical. For example, it is possible to achieve a data rate approaching approximately 56 Kb/s in the downstream direction (from central site to end-point), but the data rate in the upstream direction (end-point to central site) is limited to approximately 33.6 Kb/s because of the analog two wire connection between the end-point V.90 modem and the central office serving the end-point.
While there are some situations in which this asymmetrical data transfer may be acceptable, there are other instances in which it would be desirable to have the ability to transfer data from an end-point to a central site at a faster rate.
FIG. 1 is a block diagram illustrating an existing point-to-point analog communication environment 11. Communication environment 11 is said to be point-to-point because it typically involves communication between two individual subscribers, commonly referred to as xe2x80x9cendpointxe2x80x9d locations. For example, modem 12 connects to central office 16 via two wire analog connection 14, and modem 24 connects to central office 21 via two wire analog connection 22. Modem 12 may be located at a customer premises and modem 24 may be located at a remote customer premises. The two wire analog connections 14 and 22 are the copper wire pair that extends between a telephone company central office and an individual subscriber location, and are sometimes referred to as the xe2x80x9csubscriber loopxe2x80x9d.
Central office 16 typically connects to central office 21 via four wire digital connection 18. The four wire digital connection 18 is typically a high speed trunk comprised of, for example but not limited to, T1/E1, or a synchronous optical network (SONET). This four wire digital connection 18 is typically the high speed backbone that interconnects a plurality of telephone company central offices.
In the above-described point-to-point communication environment 11, the maximum bi-directional data transfer speed is typically on the order to 33.6 kilobits per second (Kb/s). The data rate is typically limited by two wire analog connections 14 and 22 because, in order to maintain bidirectional communication over two wires, it is necessary to filter the transmit and receive signals in order to eliminate interference. This filtering typically limits the data rate over the two wire analog connection to a maximum of approximately 33.6 Kb/s.
While modems 12 and 24 may be capable of higher speed communications, they are typically limited by the two wire analog connection 14 and 22. For example, it is possible to install a modem complying with the V.90 standard, however, because of the two wire analog connection that exists between each modem and its respective central office, the maximum achievable speed over the two wire analog connection is limited to approximately 33.6 Kb/s by the V.34 standard. It would be desirable to have the ability to implement a higher data rate from modem 12 to modem 24, or to another endpoint modem (not shown).
FIG. 2 is a block diagram illustrating an existing V.90 communication environment 31 The communication environment 31 shown in FIG. 2 is similar to point-to-point communication environment 11 with the exception that a four wire digital connection 42 exists between central office 41 and modem 44. Modem 32, which is compatible with the V.90 standard, is considered an end-point modem and is located at an individual subscriber location. Modem 32 connects to central office 36 via the above-mentioned two wire analog connection 34. Central office 36 connects to central office 41 via a four wire digital connection 38, that is similar to four wire digital connection 18 described above with respect to FIG. 1.
Typically, modem 44, which also complies with the V.90 communication standard, is considered a central site modem and is generally located at a service provider location. An example of a service provider location would be an Internet service provider (ISP). Because modem 44 is located at a service provider location that typically has access to a four wire digital connection to central office 41, it is possible to implement a higher data rate in the direction of central site modem 44 towards end-point modem 32. This direction is typically referred to as the xe2x80x9cdownstreamxe2x80x9d direction. When central site modem 44 and end-point modem 32 are operating in compliance with the V.90 standard, the data rate between central site modem 44 and end-point modem 32 approaches 56 Kb/s.
The data rate in the xe2x80x9cupstreamxe2x80x9d direction, which is the direction from end-point modem 32 to central site modem 44, is still limited to a maximum data rate of approximately 33.6 Kb/s because of the two wire analog connection 34 between end-point modem 32 and central office 36.
This scheme works well in the situation where it is desirable to have a faster data rate from central site modem 44 to end-point modem 32 than from end-point modem 32 to central site modem 44. However, there are instances when it would be desirable to have the ability to implement a higher data rate in the direction from end-point modem 32 to central site modem 44.
The invention allows a customer premises, or end-point, communication location to appear to a remote end-point location as a central site communication location. The invention provides a communication system, comprising: a first communication device including a digital connection residing at a first location; a second communication device coupled to the first communication device, the second communication device residing at a second location remote from the first location; and a V.90 modem coupled to the first communication device via the digital connection.
The invention may also be conceptualized as a method for communication, comprising the steps of: coupling a first communication device including a digital connection, the first communication device residing at a first location, to a V.90 modem via the digital connection; coupling a second communication device residing at a second location that is remote from the first location to the first communication device; and communicating from the first communication device to the second communication device at a rate faster than a communication rate from the second communication device to the first communication device.
The invention has numerous advantages, a few of which are delineated hereafter, as merely examples.
An advantage of the invention is that it permits a customer premises, or end-point, communication location to appear to another communication end-point as a central site.
Another advantage of the invention is that it allows a communication end-point to communicate with another communication end-point, or with a service provider, at data rates that have been heretofore unachievable.
Another advantage of the present invention is that it is simple in design, reliable in operation, and its design lends itself to economical mass production in modems.
Other features and advantages of the present invention will become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional features and advantages be included herein within the scope of the present invention, as defined in the appended claims.